Today's network services are unable to report realtime health assessment of the Internet to the users that are meaningful to their daily tasks like web browsing, conferencing, etc. Moreover, when the Internet connectivity is broken, neither could they notify the users the disruption of internet connectivity in a timely manner nor could they provide useful diagnostics information to the users as to where the problem might be, whether it is with their local ISP network or the Internet backbone. In addition, because of this lack of support for determining the Internet connectivity, applications that rely on this information to be available readily and reliably often have to seek out other ad-hoc and un-reliable methods such as ping certain sites. Due to intrusive nature of those methods, it is prohibitively expensive in term of generated network traffic to deploy them in a large scale.